Sealing ring with a pulsar ring for a rotary encoder

Abstract

A pulsar ring for a rotary encoder has a mounting ring ( 1 ) made of a non-magnetic material, with one end being fixed to an inner ring ( 202 ) at the rotation side and the other end being positioned in proximity to an outer ring ( 201 ) at the stationary side via labyrinth-shaped clearances (G 1 , G 2 , G 3 ), a pulsar ring body ( 2 ) formed by a synthetic resin material or rubber-like elastic material mixed with magnetic powder, magnetized to have multiple poles, and integrally installed on an inner surface of the mounting ring ( 1 ), and a seal ring ( 3 ) disposed inside the mounting ring ( 1 ), fixed to the inner ring ( 202 ) via the mounting ring ( 1 ), and slidably in contact with the outer ring ( 201 ), whereby the pulsar ring is hardly exposed to disturbances by foreign matters, muddy water, and external magnetic fields from the outside, and consequently can maintain a stable magnetic pattern.

1. A sealing device with a pulsar ring for a rotary encoder, comprising:
 a mounting ring made of a non-magnetic material, with one end being tightly fitted and fixed to a rotary side member and the other end being positioned in proximity to a stationary side member via clearances defining labyrinth seal structure; 
 a pulsar ring main body formed by a synthetic resin or an elastomeric material mixed with magnetic powder, magnetized so as to have multiple poles and integrally provided on an inner side surface of said mounting ring; and 
 a seal ring arranged in an inner side of the mounting ring; 
 wherein said seal ring includes an inner annular ring tightly fitted and fixed to said one end of the mounting ring, and a seal lip formed integrally with the inner annular ring, and slidably close contacting with the stationary side member. 
 
     
     
       2. A sealing device with a pulsar ring for a rotary encoder as claimed in  claim 1 , wherein the pulsar ring main body is in close contact with the seal ring.